1. Field of the Invention
This invention relates to therepeutic agents, which are novel derivatives of quinazoline, and is particularly concerned with such derivatives having a substituted piperidino group in the 4-position. The compounds of the invention are phosphodiesterase inhibitors and cardiac stimulants.
The compounds are useful in the curative or prophylactic treatment of cardiac conditions, particularly heart failure.
2. Description of the Prior Art
Quinazoline compounds, especially those substituted at the 2- and/or the 4-positions with various groups are known to exhibit valuable therapeutic properties. U.S. Pat. Nos. 3,517,005; 3,594,480 and 3,812,127 describe 6,7-dialkoxy-4-[4-(substituted)piperidino]quinazolines wherein the 4-substituent is, for example, alkyl, aryloxycarbonyl, alkoxycarbonyl and substituted alkoxycarbonyl wherein said substituent is formamido, alkylamido, amino, mono- and dialkylamino, which are useful as bronchodilators and as antihypertensive agents.
U.S. Pat. No. 4,001,422 discloses a series of 6,7-dialkoxy-4-substituted quinazolines wherein the 4-substituent is, inter alia ##STR1## wherein Z is -CH.sub.2 -COR.degree.; -N(Y.sub.1)-COR.degree.; -N(Y.sub.1)SO.sub.2 R.degree.; -N(Y.sub.1)-SO.sub.2 NXY.sub.2 ; -CH.sub.2 -CONXY.sub.2 ; -OCO-NXY.sub.2 and -N(Y.sub.1)-CONXY.sub.2 wherein R.degree. is lower alkyl or aryl; each of X and Y.sub.1 is hydrogen or lower alkyl; and Y.sub.2 is hydrogen, lower alkyl or aryl, said compounds being useful as cardiac stimulants.